1. Field of the Invention
The present invention relates to scales, such as those used by draftsmen and engineers, in, as an example, preparation and perusal of drawings requiring accuracy of measurements of item(s) illustrated in the drawings. More particularly, the invention relates to a structure that is compact, provides an unlimited number of scales thereon, incorporating some scales not presently available, and which includes an accessory for isolating a particular scale selected for use from other available scales.
2. Prior Art
Heretofore, various forms of scales for use in creating hand drawings have been proposed. Such scales have also incorporated more than one set of graduations thereon. However, each such scale has typically been restricted to providing a particular class of graduations thereon, such as providing only commonly used engineering scale graduations, commonly used architectural scale graduations, etc. Further, certain graduated scales have heretofore been impossible to find, such as an English scale having odd numbered increments over thirds, such as fifths, (i.e, 5/32, 5/16, 5/8, etc.), sevenths, ninths, etc., as well as certain unavailable metric scales. Still further, the scale embodiments presently available are of substantial size and, with several often being necessary for use in a single project, produce a cumbersome load which is not simply transportable, such as within a shirt pocket.